GOT GAME: Melanie Oudin gets pointers at the Open from coach Brian de Villiers, who allegedly had an affair with her mom, Leslie. Photo: AP

Melanie Oudin’s coach told her she would have to make a lot of sacrifices if she wanted a shot at the US Open title — but he never said her parent’s marriage would be one of them.

On top of all the pressure the 17-year-old tennis player from Georgia faced as she made her improbable run to the tournament’s quarterfinals this week was the knowledge that news of the affair her mother, Leslie, allegedly had with her coach, Brian de Villiers, was about to become public.

The alleged affair was first aired in divorce court by Melanie’s father, John, according to papers filed in Cobb County, Ga., Superior Court.

John Oudin filed for divorce in July 2008 and, according to Sports Illustrated, after Leslie Oudin denied adultery, he decided to make a statement under oath — and name his daughter’s coach as his wife’s lover.

“I didn’t initial [sic] take any action regarding my early suspicions because I didn’t want to believe my wife was having an affair with my daughter’s tennis coach,” he said in the statement.

“On December 29, 2007, I confronted my wife about whether she was having an affair with Brian de Villiers. I confronted Brian de Villiers separately. My wife and Brian de Villiers both admitted to me they were having an affair.”

Under terms reached by the couple in December 2008, Leslie Oudin agreed to “not interact with Brian de Villiers except as it specifically relates to the children’s tennis activities . . . [and] not to travel with Brian de Villiers to any tennis tournaments in which the children are participating.”

News of the affair broke just hours after Melanie Oudin was eliminated Wednesday night.

Sources close to the star told The Post that her normally steely nerves may have been shaken.

“She got annoyed, and you could see that. She couldn’t get herself back in the game,” a source said.

The Oudins and the coach did not return calls for comment.

Hours before her daughter’s straight-sets defeat by Caroline Wozniacki of Denmark, Leslie Oudin succeeded in getting a judge to seal the divorce file.

De Villiers, meanwhile, pulled down his Facebook page.

Oudin’s mother was by her side throughout the US Open as the unseeded tennis star defeated Russian powerhouses Maria Sharapova and Nadia Petrova. John Oudin arrived in Flushing Meadows for her fourth-round match.

The parents sat in the players box, but in different rows.

John Oudin returned to Georgia hours before the rest of the family, friends said.